Is this considered warped?

[olliec420]

I’ve been playing with ku band again the last week or so. Pulled out the old dish and just don’t feel like I’m getting good results. I got a $30 receiver for the garage because it’s hot and humid and nasty in there. lm finding 91 no problem but having trouble with 99. The q% levels on 91 on n1 are 40 tops. I feel like this should be pulling in better than that. Is the dish warped because the strings don’t touch? There is about an inch between them.

 

[harshness]

There appear to be only three Ku transponders in use at 99W. It would be easy to miss them.

 

[Magic Static]

Is the dish warped because the strings don’t touch? There is about an inch between them.

Something isn't straight. A picture showing the whole dish with the strings attached my shed some light on the problem.

 

[olliec420]

There appear to be only three Ku transponders in use at 99W. It would be easy to miss them.

I got it. 55% on the Russian tp. I feel like I should be able to do better than that. Trying to get 12094 and it’s seeing it on blind but not scanning in the channel.

 

[olliec420]

Something isn't straight. A picture showing the whole dish with the strings attached my shed some light on the problem.

It’s getting dark so that’s best I could do.

 

[Magic Static]

Yes it does look like the dish is warped.

 

[KE4EST]

Yes it does look like the dish is warped.

Agreed.

 

[olliec420]

Yes it does look like the dish is warped.

It’s ok. I’ve had it since at least 09. I guess it’s time. That explains why I can’t get a signal worth a damn. I was thinking it was me being a bad satellite guy but no, it’s the dish. I really want one of the 120 cm ones but that shipping! How can I get around that? And what is the OD of the polar mount on it? Does anyone know?

 

[danristheman]

Warped like my sense of humor.

 

[a33]

Well, what about de-warping?

First check if the warp is purely horizontal/vertical, or at an angle to hor/vert.
What I once did (with a warped Triax 78) was: lying the dish (with mount and arm) on its back, and push down the sides that should be more backwards.
Push a bit further than the wanted outcome, and the bending result will end somewhere inbetween.
Then check (with the stringtest, or on a flat surface) how much more bending you have to do.
I got a very good outcome that way.

And I've seen a film I guess on youtube, where someone in a factory hall dewarped a dish by giving it (dish without arm and mount) a big shake.
I believe the procedure was moving it away from you (while holding it at the sides), and then suddenly pulling it back, thus causing the bending in the desired direction.
Never tried that, though.
Edit: Found it:


Thankfully the rim of the dish is the structure, that allowes dewarping back to the elliptical form.

Greetz,
A33

 

[RimaNTSS]

olliec420 Unfortunately warping of metal dishes is common issue. It caused by weight of the feed, weight of the antenna, weather influence, metal tiredness etc. Warping can also happen to glass dishes, and some producers even build-in shape correction possibilities. Simple de-warping will probably give you some immediate effect, but after short period of time dish will warp again. The best method to get rid of warpage is to apply constant backward pulling of edges of the antenna. I could not find proper picture, so made this decoration (attached picture) on one of my antennas. Basically, you just need to attach metal wire to the edges of the dish and then pull back the wire. It is possible to use turn-buckle to regulate the strength of pulling.

 

[a33]

RimaNTSS : Your solution seems good to pull back the sides of the dish.
That would be 'normal' warpage?

However in the picture of olliec420 , it looks like the top and bottom must be pulled back.
Don't know the cause of that.
Maybe the side arms have something to do with that?

Greetz,
A33

 

[RimaNTSS]

Yes, unusual warpage. Maybe more radical methods can be used... get another dish , bigger and better, like Channel Master 1.2m

 

[olliec420]

Ahhh, I didn’t know de warping was an option. Worth a try I guess!

Since I moved in 2014 this dish has been laying around the yard and on my “portable” bucket mount. Been knocked over by the wind countless times. That musta have been what did it.

So I just got the bug to play with ku again and I made a little setup in the garage and this is on the side yard. I have a 1.8 prodelin that I got for $60 but I feel like that’s a little too big for side yard. Haha. No HOA but I’m sure the neighbors wouldn’t appreciate.

 

[olliec420]

May have fixed it!

Hell I might have bent it tuning it. Sometime I pull hard on it to make tiny adjustments. I’ll try not to do that this time.

 

[comfortably_numb]

There appear to be only three Ku transponders in use at 99W. It would be easy to miss them.

There are quite a few more than that, but not easy to tune without at least a 1.2m dish.

 

[raydio]

Well, what about de-warping?

First check if the warp is purely horizontal/vertical, or at an angle to hor/vert.
What I once did (with a warped Triax 78) was: lying the dish (with mount and arm) on its back, and push down the sides that should be more backwards.
Push a bit further than the wanted outcome, and the bending result will end somewhere inbetween.
Then check (with the stringtest, or on a flat surface) how much more bending you have to do.
I got a very good outcome that way.

And I've seen a film I guess on youtube, where someone in a factory hall dewarped a dish by giving it (dish without arm and mount) a big shake.
I believe the procedure was moving it away from you (while holding it at the sides), and then suddenly pulling it back, thus causing the bending in the desired direction.
Never tried that, though.
Edit: Found it:


Thankfully the rim of the dish is the structure, that allowes dewarping back to the elliptical form.

Greetz,
A33

Ya, how did he say in the video - shake it like a baby?

 

[comfortably_numb]

Ya, how did he say in the video - shake it like a baby?

 

[olliec420]

There are quite a few more than that, but not easy to tune without at least a 1.2m dish.

This is why I think I should just order a bigger dish. But if this 36 bends so easy, how easy does the geosatpro 48 in bend?

Ya, how did he say in the video - shake it like a baby?

Yeah I thought that was funny. In mother Russia, baby shake you!



I’m already getting a few more TPs on scan of 91but no more channels. Time to fine tune without bending it again. I have a tbs 6922 I’m putting in an old pc to bring in the garage today. Hopefully it’s tuner is more sensitive than this $30 jobbie.

 

[comfortably_numb]

The GeoSat Pro 1.2m is made of the same material as the 90cm. It's delivered by freight courier in a large box. You may have to do the "shake test" when it arrives, same as the 90cm. Mine performs very well, and it's large enough that I can focus it on 99, and use offset LNB's to get everything on 95 and 103 as well.